Pneumatic pressure molded impact countermeasure

ABSTRACT

An impact countermeasure device ( 30 ) used for receiving an impact force ( 56 ) has a generally hollow body with an outer wall ( 52 ) defining an interior portion ( 54 ) and an exterior portion. The wall ( 52 ) has at least one blow hole ( 60 ) therethrough. The wall ( 52 ) has at least one tack off area ( 70 ) formed therein. The tack off area ( 70 ) and the blow hole ( 60 ) control the crush rate of the body in response to the impact force ( 56 ).

BACKGROUND OF INVENTION

The present invention relates generally to impact countermeasures forautomotive vehicles, and more particularly, to hollow countermeasuresstructures used to reduce the force of impact on various portions of theinterior of the automotive vehicle.

Resilient pads have been used to protect vehicle occupants from contactwith the interior structure of the vehicle during an impact. One commonway in which to prevent contact with the interior structure is toprovide airbags. Airbags have been employed both in front and in sideimpact areas. However, airbags do not completely protect the vehicleoccupant. Other areas of contact for the vehicle occupants may includethe body pillars, roof structure, door header and the like. Commonly,expanded foam pads are employed in such areas. Expanded foam pads areformed of molded and expanded polypropylene or polystyrene foam. Usingmolded expanded polypropylene or polystyrene foam requires the use oflong cycle time processes. Such materials are relatively expensive andthe processes are expensive in that they are time consuming to form apart.

Another drawback to such devices is that as the design evolves for aparticular automotive vehicle, the parts may have to be substantiallyreworked during the process.

It would therefore be desirable to provide a method for forming animpact countermeasure that is flexible to allow easy design changes aswell as uses low cost materials and low processing times.

SUMMARY OF INVENTION

The present invention provides a countermeasure that uses a blow moldingprocess to form a hollow part.

In one aspect of the invention, a countermeasure for receiving an impactforce has a generally hollow device body that has an outer wall definingan interior portion and an exterior portion. The wall has at least oneblow hole therethrough. The wall has at least one tack off area formedtherein. The tack off area and the blow hole control the crush rate ofthe body in response to the impact force.

In a further aspect of the invention, a method for operating acountermeasure device comprises directing an impact force at a generallyhollow device, counteracting the impact force by releasing air through ablow hole in a predetermined rate in response to the impact, andcounteracting the impact by controllably crushing a tack off area.

In a further aspect of the invention, a method for making acountermeasure device comprises blow molding a device having a generallyhollow device body having an outer wall defining an interior portion andan exterior portion, forming at least one blow hole through the outerwall, forming at least one tack off area in the outer wall, andachieving a crush rate by sizing the tack off area and said blow hole.

One advantage of the invention is that the blow molding process has asubstantially reduced cycle time than the foam processes described inthe background of the invention. Another advantage of the invention isthat the device is easily tunable for different impacts by controllingthe blow hole size. Thus, if the requirements of the vehicle arechanged, the blow hole may be easily changed.

Another advantage of the invention is that the angles of the sidewallsof the tack off area may be easily changed or the shape may be changedto change the crushing characteristic of the device without having tochange the entire device design.

Other advantages and features of the present invention will becomeapparent when viewed in light of the detailed description of thepreferred embodiment when taken in conjunction with the attacheddrawings and appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cutaway side view of an automotive vehicle having severaldevices formed according to the present invention.

FIG. 2 is a perspective view of a countermeasure device formed accordingto the present invention.

FIG. 3 is a cross-sectional view of a countermeasure device of FIG. 2.

FIG. 4 is a second cross-sectional view of a countermeasure deviceformed according to the present invention.

DETAILED DESCRIPTION

In the following figures the same reference numerals will be used toillustrate the same components.

The present invention is described with respect to variousimplementations of countermeasure devices. However, those skilled in theart will recognize other applications for the implementation of impactcountermeasures of the present invention.

Referring now to FIG. 1, an automotive vehicle 10 is shown having avehicle occupant 12 positioned with respect to an A pillar 14, a Bpillar 16, an instrument panel 18, a headliner 20, and a door 22. A Cpillar 24 is also illustrated. Devices formed according to the presentinvention may include a knee bolster device 26 positioned beneath theinstrument panel, an A pillar device 28 positioned on A pillar 14 of thepresent invention, a door device 30 positioned on door 22 of theautomotive vehicle, a door header device 32 positioned on the header ofdoor 22 of the automotive vehicle, a B pillar device 34 positioned onthe B pillar of the automotive vehicle, a C pillar device 36 positionedon the C pillar 24 of the automotive vehicle, a headliner device 38positioned on the headliner 20 of the vehicle. Of course, those skilledin the art will recognize that a rear door device may also be includedsimilar to the door device described above. Also, devices formedaccording to the teachings herein may be located at various other placesof the vehicle. For example, in a van or SUV, the D pillar may also havesuch devices as well as the rear window header or inside the rearquarter panel. Essentially, any place an occupant may contact thevehicle structure may include such a device.

Referring now to FIGS. 2, 3, and 4, door bolster device 30 isillustrated in further detail. It should be noted that although a doorbolster device 30 is illustrated, the teachings of the present inventionare equally applicable to any of the other types of devices describedabove. As can be seen, door device 30 has a generally hollow body 50.The hollow body is defined by an outer wall 52 disposed therearound.Thus, outer wall 52 defines an interior portion 54 and an exteriorportion outside of the outer wall 52. As will be further describedbelow, the outer wall 52 are preferably blow molded to form the device30. The blow molded outer wall 52 allow for the device to absorb energywhen crushed by an impact force 56. Generally, the impact forcerepresented by arrows 56 are generally perpendicular to the outersurface of the device 30. As shown, the outer wall 52 of the device maybe irregularly shaped, however, the direction of impact for theparticular part is generally known. Thus, the device may be designed todissipate the maximum impact force.

A blow hole 60 through outer wall 52 may be sized to control the crushrate of the device 30. By sizing the blow hole larger, the device willcrush at a faster rate than if the hole 60 is smaller.

The device 30 generally has a front wall 62 and a rear wall 64. Frontwall 62 and rear wall 64 are oriented relative to the direction ofimpact 56. That is, front wall 62 receives the impact which, aftercrushing, the impact tends toward rear wall 64. As the device crushes,the blow hole releases the air therefrom and controls the crush ratethereof.

A tack off area 70 is formed in the device. Tack off area 70 iscomprised of a first area 72 of front wall 62 and a second area 74 ofrear wall 64 that are positioned directly adjacent to each other. In thepreferred embodiment, the first area 72 and the second area 74 aretouching each other. The first area 72 and the second area 74 arepreferably positioned near the middle of the device. That is, the firstarea 72 and the second area 74 are preferably positioned somewherebetween front wall 62 and rear wall 64. The first area 72 is coupled tofront wall 62 by an angular front wall 76. Angular front wall 76 isgenerally conical in shape and has an angle α relative to the angle ofimpact. As illustrated, angular front wall 76 is generally conical incross-section.

An angular rear wall 78 couples second area 74 to rear wall 64. Asillustrated, angular rear wall 78 has an angle β with respect to thedirection of impact 56. By changing the angles α and β, the crush rateof the entire device may be changed.

As is best shown in FIG. 3, the crush rate may also be changed byproviding discontinuities or corrugations 80 in the angular front wall76. Thus, when looking within the device the discontinuities orcorrugations 80 appear as continuous rings of angular front wall 76.

Referring now to FIG. 4, a tack off area 84 is shown. Tack off area 84is disposed rearwardly from the first tack off area 70. A tack off area84 may be used for attaching the device to the structure of the vehicle.Thus, tack off area 84 may have a fastener or the like therethrough.

In operation, when the device is subjected to an impact force 56, theimpacting force is counteracted in two ways. First, the air iscontrollably released through one or more blow holes and therefore thecrush rate may be controlled thereby. In a second respect, the angles ofthe tack off walls and the presence or absence of discontinuitieschanges the crush rate of the device particularly in the area of thedevice receiving the most impact. That is, as is best shown in FIG. 4,the tack off area 70 along with the blow hole 70 will counteract themost impact for the device.

To form the device the body of the device is preferably blow molded.Portions of the device are tacked off so that the device is not hollowat the tack off areas. By blow molding the device an interior portionand exterior portion are defined. Blow holes may be formed during theblow molding process or formed immediately thereafter by drilling,cutting, or the like. Thus, when a force is imparted upon the device,both the tack off area and the presence and size of the blow holecounteract the force thereby.

While particular embodiments of the invention have been shown anddescribed, numerous variations and alternate embodiments will occur tothose skilled in the art. Accordingly, it is intended that the inventionbe limited only in terms of the appended claims.

What is claimed is:
 1. An impact countermeasure device for receiving animpact force having an impact direction comprising: a generally hollowdevice body having an outer wall defining an interior portion and anexterior portion, said outer wall having at least one blow holetherethrough; and said outer wall having at least one tack off areaformed therein, said tack off area and said blow hole controlling acrush rate of said body in response to the impact force.
 2. An impactcountermeasure device as recited in claim 1 wherein outer wall having afront wall and a rear wall, said tack off area comprising a first areaof said front wall disposed directly adjacent to a second area of saidrear wall.
 3. An impact countermeasure device as recited in claim 2wherein said outer wall having a front wall having a first area and arear wall having a second area, said first area and said second areadisposed between said front wall and said rear wall.
 4. An impactcountermeasure device as recited in claim 3 wherein said tack off areacomprises a first angular wall coupled between said first area and saidfront wall, and a second angular wall coupled between said second areaand said rear wall.
 5. An impact countermeasure device as recited inclaim 4 wherein said first angular wall is disposed at an angle withrespect to said direction of impact.
 6. An impact countermeasure deviceas recited in claim 5 wherein said angle is 0 to 45 degrees.
 7. Animpact countermeasure device as recited in claim 4 wherein said firstangular wall is non-linear.
 8. An impact countermeasure device asrecited in claim 5 wherein said first angular wall is stepped.
 9. Animpact countermeasure device as recited in claim 4 wherein said secondangular wall is non-linear.
 10. An impact countermeasure device asrecited in claim 9 wherein said second angular wall is stepped.
 11. Animpact countermeasure device as recited in claim 3 wherein said firstarea and said second area are disposed generally perpendicular to theimpact direction.
 12. An impact countermeasure device as recited inclaim 1 wherein the device is blow-molded.
 13. An impact countermeasuredevice as recited in claim 1 wherein said body is composed ofpolypropylene or polyethylene.
 14. A headliner comprising: an impactcountermeasure device comprising a generally hollow device body havingan outer wall defining an interior portion and an exterior portion, saidouter wall having at least one blow hole therethrough; and said outerwall having at least one tack off area formed therein, said tack offarea and said blow hole controlling a crush rate of said body inresponse to the impact force.
 15. A door panel comprising: an impactcountermeasure device comprising a generally hollow device body havingan outer wall defining an interior portion and an exterior portion, saidouter wall having at least one blow hole therethrough; and said outerwall having at least one tack off area formed therein, said tack offarea and said blow hole controlling a crush rate of said body inresponse to the impact force.
 16. An instrument panel comprising: animpact countermeasure device comprising a generally hollow device bodyhaving an outer wall defining an interior portion and an exteriorportion, said outer wall having at least one blow hole therethrough; andsaid outer wall having at least one tack off area formed therein, saidtack off area and said blow hole controlling a crush rate of said bodyin response to the impact force.
 17. A knee bolster comprising: animpact countermeasure device comprising a generally hollow device bodyhaving an outer wall defining an interior portion and an exteriorportion, said outer wall having at least one blow hole therethrough; andsaid outer wall having at least one tack off area formed therein, saidtack off area and said blow hole controlling a crush rate of said bodyin response to the impact force.
 18. A method of providing an impactcountermeasure comprising: directing an impact force at a generallyhollow device; counteracting the impact force by releasing air through ablow hole in a predetermined rate in response to the impact; andcounteracting the impact by controllably crushing a tack off area.
 19. Amethod of providing an impact countermeasure as recited in claim 18wherein counteracting the impact by controllably crushing angular wallsof the tack off area.